Addressing the impact of heat stress during flowering and grain filling is critical to sustaining wheat productivity to meet a steadily increasing demand from a rapidly growing world population. Crop wild progenitor species of wheat possess a wealth of genetic diversity for several biotic and abiotic stresses, and morphological traits and can serve as valuable donors. The transfer of useful variation from the diploid progenitor, Aegilops tauschii, to hexaploid wheat can be done through the generation of synthetic hexaploid wheat (SHW). The present study targeted the identification of potential primary SHWs to introduce new genetic variability for heat stress tolerance. Selected SHWs were screened for different yield-associated traits along with three advanced breeding lines and durum parents as checks for assessing terminal heat stress tolerance under timely and late sown conditions for two consecutive seasons. Heat tolerance index based on the number of productive tillers and thousand grain weight indicated that three synthetics, syn9809 (64.32, 78.80), syn14128 (50.30, 78.28) and syn14135 (58.16, 76.03), were able to endure terminal heat stress better than other SHWs as well as checks. One of these synthetics, syn14128, recorded a minimum reduction in thousand kernel weight (21%), chlorophyll content (2.56%), grain width (1.07%) despite minimum grain-filling duration (36.15 d) and has been selected as a potential candidate for introducing the terminal heat stress tolerance in wheat breeding programmes. Breeding efforts using these candidate donors will help develop lines with a higher potential to express the desired heat stress-tolerant phenotype under field conditions.

中文翻译：

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评价硬粒小麦-粗纹伊蚊衍生的初级合成物作为小麦改良耐热胁迫的潜在来源

解决开花和灌浆期间热应激的影响对于维持小麦生产力以满足快速增长的世界人口稳步增长的需求至关重要。小麦的作物野生祖种具有丰富的遗传多样性，可应对多种生物和非生物胁迫以及形态特征，可作为有价值的供体。从二倍体祖细胞转移有用的变异，粗纹伊蚊，六倍体小麦可以通过合成六倍体小麦（SHW）来完成。本研究的目标是识别潜在的初级 SHW，以引入新的热应激耐受性遗传变异性。筛选出的 SHW 与三个先进的育种系和硬粒小麦亲本一起筛选不同的产量相关性状，作为在连续两个季节适时和晚播条件下评估终末热应激耐受性的检查。基于生产分蘖数和千粒重的耐热指数表明，syn9809 (64.32, 78.80)、syn14128 (50.30, 78.28) 和 syn14135 (58.16, 76.03) 3 种合成品种对终端热胁迫的耐受性优于其他品种。 SHW 和支票。其中一种合成物 syn14128 记录了千粒重的最小减少 (21%)，叶绿素含量（2.56%），籽粒宽度（1.07%），尽管灌浆持续时间最短（36.15 d），并且已被选为在小麦育种计划中引入终端耐热胁迫的潜在候选者。使用这些候选供体的育种工作将有助于开发具有更高潜力的品系，以在田间条件下表达所需的耐热胁迫表型。